For years now I've used eukanuba lamb and rice formula. I just recently switched the Costco brand, see to be OK. I remember when I was a kid my father would feed our dogs table scraps, a can of horse meat once in a while they basicly ate whatever. One lived to 17 the other to 19, these were both mutts someone gave us when their dog had puppies. So I don't know or I not convinced all these new designer brands do anything other than cost more. These dogs back then never went to the vet I don't even know if they even had shots, maybe rabies. My point is a dog lived ~15 years then and they still live about 15 years today. Now if these new brands gave us an average life span of 20 years I'd say they were on to somting otherwise, IMO it just costs more and make us feel like we're doing something.
One other thing I wanted to mention, my father and grandfather used to worm puppies with raw garlic, crushed red pepper and olive oil. No meds. My grandfather told me in Italian the garlic and pepper would kill them, the olive oil would make everything slide out. I guessed it worked.